SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '86803fd32841ea60c07dd4c83e48702504f765a39239c94c9ccdaa8764c1650c' 
  AND token = '3JL/ZUfHhrcwtvM3/8Jf5BGl/bb7ZWYu9b2cMOphw68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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