SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e59380213034adfbbdd0a20a7110a59463d693c43c5ece1343604b5e81c4d6f' 
  AND token = '6YiGJhQlOcWh31cjm3MUD9fYBF6YHfPmyHiZg3w4Ji8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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