SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1a523cb6b9f29729a8347d1d989f818b99528d15ae5187c5f48475b4e481b835' 
  AND token = 'K20omIOSf/m3Ve2kH6CK8kECj7vh7PTG3wKEYH+VC5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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