SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd408ece7c2f3976238aa8a096c2fa2bbe20a36755c1eb7a1425d03c06fbe1da2' 
  AND token = 'jCZUmhhEKYVdNKWPc+ErShrllnDhIW9bSma1qTYoGu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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