SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fb26a72356d21301b519c6e11453f7af54355eefbd0dd11c61bffb3c2854184' 
  AND token = 'tFgB42ZRldg73CWFxgki0mMFHCtH/VXkPIvqi053jTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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