SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fc6ac63de1523f7f46abb24820d92e5b73001b4eb6bd99d05fc4f131c2052c0' 
  AND token = 'EgxUBRniwN4lLWGPgzlmcK0vxmyV5j4m0TJnqpDhPb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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