SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ec1d675937bc19ce5c9ae837fe8a7e382e03b42b134d42c081bb203de04da7b' 
  AND token = 'mpcBZyZxmiaOerLCiUmsfqbRE9sl3pxLf1rfpMEgqVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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