SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0456d44a8afb611f973df321aa66094f6c67031fff1569239ba7001c80c1fd14' 
  AND token = 'pF0doHoocJFh0YJDsiMMVFSQEolSh/NS04YgLsVQSx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}