SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43ce7226c1b462affc14d3e1d89c3f189724b37f58842a12bd9dd661e14f45be' 
  AND token = 'oCbZDQtuYdZNNI9V+cubCMfAJ4INeGefcnjV6UaxgCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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