SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feca5e5a79917ebff544c902788aa83bb50f69c460517b16088e18634fb6a16f' 
  AND token = '/ltVBoJ1MtcjurES2b/tidjsnj1e1Slyxt1kTKBwz3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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