SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7341bfe4b91a6e4db0b4be5a2faaf191f1ff68e4c2e846c7582770df2ea8d9c' 
  AND token = 'O1waX3vBV0A12+d4DBzGIHOe17Geis7yaGjnwUrJ5sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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