SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16cc25795b714e3aef726b1bd64a561a0372152dacb5286f6b22aef3dfcfee3f' 
  AND token = 'ulVMEkVKejYEkoLU0Ok0QMhrBgoNzfhOJx7qsuuWtcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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