SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86db5338ebae4accc958aedcc0a479335dfb943e762a5dd38954e018c6eba5e5' 
  AND token = 'O02r+GSoZwKExE2/DA7T/jQC27dVT8cpUuTb5JPbkf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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