SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fdd29a6a425b55fadaa5f4d0e452a2ecddc22bcad83b1def1d9419a29d502ad' 
  AND token = '67fHV1paLJ+mjAXKinTuSaVsDVXx55tVoLndN4etgww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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