SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c86717692e9b5c3c403b5578579f4af53d301730606650a3b6b2fbba3b0fbd55' 
  AND token = 'D1arpHkzl/EXMcHXgHsTPfMVOj5J65IZthx6mYCLnao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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