Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd55ed50e46f39f0359f4f0b489348bafad3f1034bfeefb4c8da6ea11b1464f93' 
  AND token = 's9dR5bK6uqkUIR3yMsN2gkiQ3KFjnm2+RwgtUEy2VlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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