SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2ef73705d7cd68755bd2e1bb3581f4f660b3f4efe31538eb158c51b2599b96b' 
  AND token = '0Hd2FWZRjvnvLVIkGX6Ef9AfICAnX7WRpd1WgzagdW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}