SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba03b02fc943474aa071e95674c51c803c25d4bdd1bf6137cc21e4ebab1c9746' 
  AND token = 'JxglP5xgWIA+ZaSosaVAR9OkTbM8/Ksw2Eq5dVDRujc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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