SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '550d185d5fbfbbc73634ded2c3a290e3604b6aa1c8c9c7267723f853b7a5b202' 
  AND token = 'v1Pji9dCuUeC6s2PGg3gh0ukzxqH9DJmX7OwFFlvQs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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