SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2976cf7e33a60e5806c49f45600427feb46b70bb196a5144c1b807224d0df0e' 
  AND token = 'poP3Zc11N15V+5zeeXzW9cv1PwsBzqR/szH+Jl6xpjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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