SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2a4872243571f0da6cb265930e7e510d9c28d10dc4cc80dca4b29d275810f41a' 
  AND token = 'kvsFqNRGFrPP5XQiGGXWdTww3/c2ceCdtWXZ2WHSeB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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