SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '178a0703a8d114c4c5e005d5da58fd4f3deeeb1fa480b515230de50970b17031' 
  AND token = 's7RcfdM/TpoR4jICr5N5rHmpfEJL7omAAjWNcZHFvLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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