SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f105c5a64329ae327ea18384ebc4515edb526da1502c59c02f510eef736b539' 
  AND token = 'UueaJ3sst7VQwGjMjbUDAQ2a3QVdDqes/CqMNjZD32s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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