SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4708cf7654f95793c3633128b3f543ff8daec38510b3fc7d1873a663a1b1755' 
  AND token = 'ssahHadZlI3+ZVmJEiRC17M2jcjx5WWA4lAOLpQprKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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