SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d03ce64860d0ca8a49e18d91e49afaa038727f40d93c857afb965befc401cad' 
  AND token = 'QQqC6DBc8Toi2fWS1QdtC7gfxZQulz0KxrUGOM9s8Jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}