SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a36f3d6477f9514b2f53120f64de6639d7ad71669904826597abac183542d523' 
  AND token = '8jsvJFkvAXrjkNXlm5uQo+6P5tKwTM+eNzPXZLuIgwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}