SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '548988317b30272b13007ee3d38a1ec6015a5c8d78f0e565e40d3c3db406426d' 
  AND token = 'QzSDlu6sgOHU+ry2NwwAw69mgFnKl7r2egGX0XVD99Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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