SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '358098acdf192ddc69a455b48dc31ecfce9eb49fd67008b8887b705c030e0590' 
  AND token = '5UFOahl5OPlSQQYOlVrHVGGYUU9fHwOcdsDRbkalr4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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