SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46e600202fd3e0ce593b16e2047b02421629b41ac043537f5e3070d29da6dbdc' 
  AND token = 'WnOB11cQUiuWmsAhilG43RGBt8axTkPiYj6xXx82lmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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