SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53608614dd382b69ce7cd4f9b8211e7898f1c0db38cc0a52b9b61fd598b5460f' 
  AND token = 'VEn4oam3igjUicEb0hqOMszxXv7Q9lqOwpKgVZ40Hw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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