SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62eb33d12ef0b03328cf58fda9d80d0030e8730ceab42974a9e896d83c4a0f73' 
  AND token = 'T1ox2dabIi8psK8eznUGekhYP0/VLJerTUhDiv56eEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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