SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e3489e93280764dda7949db5092c960d780ea86ca12d7aca02d2457867f05f70' 
  AND token = 'F1BCE3D3FVlvN1ZU+rT4SRvzO25b2OGXcJnMfXP+DkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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