SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26acd2b7a4d14c88bff13ca5ff668146e4d810171da622ebca2fb08b43b0c235' 
  AND token = 'oMY2wsHnUAtheohe4k6a8VN/x/h5aeKrqTSt0EgOhFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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