SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1e26d388e87b3099edca7c91778e2cb8c32b1de8351c16aa2722e4c7eec3079' 
  AND token = 'hMFT/mLaQLxDtan/bISC15efzvxJFGFGHEMlxAjiG88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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