SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1efa4fb951433c6fbcb81d97a83f6b9245c75b5377d7f11dc8405a2f2686886c' 
  AND token = '2vvBBqX6eA9wQahIR+hPwk8pBef62muuMme8oTJVDBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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