SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14635118c0a7dc544b4aa540f00c48dff45cb7f928c822ca028dfab3eb7f9cc1' 
  AND token = 'DuuQgEBPrwFIaOLp3Wb/+VpEUD21dzneqlKGqk9Zoog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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