SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b08b7bae4689c9ceb4444fdc0acf6424799eb9e17ce749f398999954ac8183dd' 
  AND token = 'wE2EfzeV8MfaQxHzhNoiuqsLSlomhDxHyrvJvgxvAs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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