SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3260be305d6513e97bf23a616937e515d4784a4ab3d9a19b7ff582b5e1e7f681' 
  AND token = 'tU4t45a+cchqiZ3WCCGcPViVN0er1a29niucE3JU0sU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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