SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c644625f9f0e0428ee5d40ca36da72fa95fe95fd585459f33a23237a6e47487' 
  AND token = '5m47DuPOZpoxmbSHaJcufToVMVgP8x/zbOEz8Rb+TPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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