SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1b51547f9ec1cedb51869ad195aa56da72210e12e95d44917fdf30495a0a690' 
  AND token = 'yCYwZ+Q5IZIylMzibQzUBe62Ub7YZfK4yU/NfyCEGSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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