SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e5307682470ed6f7d54627438544c053fc0b011ce5545fa8b803631af83cd74' 
  AND token = 'e9+stsl8ClvVsaKuEiCm86hH9fRVPm0tcnKT0U6YYpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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