SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '286bef699fc3ca7cee4365ba1d165c0e6056c8b7e0f02631552ece9edab992ea' 
  AND token = 'XWTHc0WWOXDoWwRQsyZrgOezg8IwaCvfQ87lDTJYKJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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