SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e4ce614c109491eb3111cf948642197c657effafe986da2c4de9fc5f22d7d4b1' 
  AND token = 'OYH+3BdGd55i73EJqqFme9BIwMDDlvRX0x9ResiulJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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