SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dcb48e5b89e347861a1f8bb08fc01842bbba0ac8c61d3abaf5b032f3d93acd4' 
  AND token = '4QPGYx4Ezh9PJZADBXTyr/XvIHXL7Cbosxdzxmnk4aI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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