SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db126559f895e9ae09b5fe72342c82931a5ee7129cc165b8cfaf7aafb86a9bd6' 
  AND token = 'KXXV1Na0KekBeqRshb3nw+OuNmdeIwBZF0gBFE9vBNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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