SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b30f754f23b396eae41b38f1e7c92de9bb03ed25ba4406b8b0c41a75a780e9f2' 
  AND token = 'j/6OoLtsePZF1X/ZzhBut8id9r9CLUQit7NhmBCIVgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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