SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bca40ac6dfd296f22d504cef821e2b15c5b4106eb533f97b1382903d7a87bc35' 
  AND token = 'LQl3/LcgmnpyEs9MdXLPDe6JjRTNKtMxb3scNSsehqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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