SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cb697838c1d31214c7f5fc33e73e3d523141a96ff9b70442fd7dd318103afbce' 
  AND token = 'w2augWy6z/7dIZ3tMnQTkpe+k/KNI4gAD0Fx6mdffPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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