SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7c86ff30bbbc3da64dbb99818a631ac2303eb50c28435b7317e8d5fcf8b749b' 
  AND token = 'O+CzrJwPZZbQtszIfVW+dK1YOpCjBkupJ84AuF+RRvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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