SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b91062b5843daf5dad1b14348266c75298f151eeafd2b160e2dd22d9b3255f83' 
  AND token = 'bFlCJ5FiNaDtp8f4n++blCsDl3JYvuwDPPmzlFw/Vqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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