SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64f08786204c992a8791a0ede90d1a432f6fa814aaf2802f0c755cb945159693' 
  AND token = 'cPgQtgX8HApvpYTZIvQD9+iS/+5AcxaO4Z/nU/9btoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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