SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeed6748f3472985d46b52ac4128d5e67936bcd7708bf3131af94345b99d5541' 
  AND token = 'v3/LVF46vRwYoWFB6gB9lO+zxsIXw0U9gDaQPNdKpYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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