SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20a0b1a63481811e2d60de8634d1f44b03d7ed66ebecabdb5a983e3164943135' 
  AND token = 'EeQ9iHPMVr9ULOTDE3ZD2KE4KD6UbJiESgMXU0bNWGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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