SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c4bdc172dd7ce1a7b087a81d07df78d50b9aa56ce90de229cd2569562ee6492' 
  AND token = 'kMV4fWTCPXboYc1WyaaKC7vDsPmQyS6OybZJT2fQzJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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