SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fccb48c69e26501eb7f9940e15e3a6c23a011639ac1574bd16acd87b0c9a8dc7' 
  AND token = 'TadG9BzAkNV30TlHY6N+dIKOuVq0rgmKMcCsALwA0OM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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