SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3d1e9aa9d3d806560a20fc45c1932d6da411a34b16db37755bdef651490dd2b' 
  AND token = 'L0zYidObI5/2cPGk7MWNgYPHtra57+vi54WDMtUOqj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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