SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '589f2df550596e9adde20f61de722f4337d11723c8bd4a492175c6fea8855250' 
  AND token = '3yKPZ/xnji6ZaZ5OqhQfBH+kMl/+MZYlpWOEo3ijLY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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