SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a37621fa7300082d80602518c2cd9a93bc2d18a6eb5bd86262969d32fa4a948c' 
  AND token = 'njfmphByWXoONIXEoHwO/t1mzFhT6QhLVhxPorS3BoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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