SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59a7c27b2a6b45c331f457d47b2a4e6b32388206dffae0b1bb86b30e427ee4cb' 
  AND token = 'KOwK2ZiXiQXNu7RI6EWHoDhTHlcLJmPDnMYx4jJsEHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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