SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c4639c11d26e0dd7abdff8e0f563dfe6709c2f919c3f3cfd82fb8d876a05516' 
  AND token = '0DZLqV4t5s7cOAlwBbgYNFi1hAqeoFcrOXe3JzIRcxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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