SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3fc854b7075c4683bfd6a99073daf482174c2414ef43ed6bba1ac1ca6d0e8986' 
  AND token = 'EauWR8wyo6QmPScxUg5hp4LXBoGVy+mKRUFX8kSPzLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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