SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cf55ccf1b2074b405465499c8d6db25a20c106d99effca7a73a3293d3006daf4' 
  AND token = 'iz/KcYxs3GEYk2eoRjlxFuwpoGERNjHDikdfWkptze4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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