SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2677c42f83670c4c190f6d45a9f0cbb18fd20d512b3138a3bd77d57321603dbb' 
  AND token = 'SHDk/d/LpMkPqfhc0764voFBsfRvdhjh9yIcxRjU1hM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00094

JSON explain

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