SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26d3d94fde6afdd9e1bc27469920e810f4bd35d7e997749454dc5119969ab902' 
  AND token = 'Qg7EhclBdHEPmvj5i5pJ5yKKZPVnftWhrz6WkNYSsoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00117

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}