SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e46d801279dae44c5a14e389118165ad29a1881101a46971543ca64f59ad7b7e' 
  AND token = '+FQuvHi+MdyuneR1kzV2C4gkMosdvSgJaevlk3F0OQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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