SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b9a7201708d88d34b7f1bf6fedbbbea58af9906a74fa23ace52c240bb536166' 
  AND token = 'QigxoMxF/jea6+v5tuBqnTPCIMC6FFYLtRw94NM+/+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}