SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87ae99f6bd658150594ac581d1952eb8bd92baaf7e336017615f568990ecc935' 
  AND token = 'ELtMJL314DvnQm4QUzzmBqjg2Q0SY+WNKrWvKn/csaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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