SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cd91edd77be639a4cc75222e0b7519fff5fd7cae7ba04d297e7c8c445a51af1c' 
  AND token = 'mnpdDfZGWndQ+kYT4nc/WXkew6auPAd0MIkvRMpPssI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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