SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '470364eee1e667d9fecdf1e65534eebdab99ddb420e43b5eba834c75bac2a7c8' 
  AND token = 'AprTC3I4mCX+7+YjJz7uKiMDNsl8x++YxsapjHBTEGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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