SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7570d632e7f7da40a55ca516278c3801fc5700683becf7cc598bc6b06b581e8b' 
  AND token = '4ej6FklJl/CImRARHfRC8y+NX4vOcpxHwcUGwrn3XlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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