SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7ceed4245fbb89bedc669420578389a63464b674810ff8379556aab28ccbdd3' 
  AND token = 'jLEVEoZYA9t89fz7OrAwNqTTe0iKOOfIlK40PIrQIKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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