SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2be35e5e88c1a8414804eeda1c57d9605038400ce2deb0ab3a662f449d2d5cf5' 
  AND token = 'Ly5NaA1yI1syvZWhe8irG0BzMrrLFdTtaK/cERwAwwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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