Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21dacbff75e284e4e0a4b6ac88b0e32e70098cb5941e22d2ad9aa0dbdaaf92a3' 
  AND token = 'q5Xs+r/dxrMtUN/SEyH6g1gzXyAH0k52NFkPv09If7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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