SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e27c0d2c2855b5dd743581dc30a45e32a9e635a1941193b59ce961e8ace4bfc' 
  AND token = 'g8xVuSWUsCS4WuweC/07JfRVvRgJ8p575Wh1MtysZBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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