SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54025107f7a9f4649bfbb21f84b03343008b5c9f163763a507d84828f26a1584' 
  AND token = 'wZHvbO5UgpY0dVM42NzY9ALF25SOZ3DvPh5klB1+R2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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